The Physicochemical and Phylogenetic Properties of Twelve Spike Glycoprotein Models For SARS-CoV-2 From China, Iran, And Tunisia

Abstract

Samih Abed Odhaiba, Miaad Jassim Mohammedb, Dina A. Jamilc, Hayder A Al-Aubaidyd

Background: The coronavirus spike glycoprotein is a trimeric structural surface protein that facilitates the viral adhesion through attaching receptors on the human cell surface. This study aims to analyze and compare the genomic and phylogenetic properties of these spike glycoprotiens from China, Iran, and Tunisia.
Methods: This is a descriptive cross-sectional comparative study for the different properties of S glycoprotein from 12 SARS-CoV-2 specimens from GenBank. Clustal Omega was used to study model sequences alignment, residual conservation, phylogeny, and identity matrix. SWISS-MODEL developed and validated the 3D models for three protein sequences with the highest model quality. The different physicochemical characteristics of different models were assessed by ExPASy proteomics.
Results: The Chinese and the Iranian sequences share 100% identity, although they have a different amino acids number, and 25-29.27% identity to the Tunisian sequences. The 12 models are monophyletic, with varying stages of evolutionary divergence. There are six fully, three highly, and five lowly conserved residues across the sequences. The resulting three highly reliable 3D models were of different global qualities, being the lowest for the Tunisian, and the highest for the Iranian models. All the models are highly hydrophilic. The Tunisian models were unstable in comparison to the relatively stable other models with different physicochemical characteristics.
Conclusion: The models had different N-terminal residues and side group’s polarity and charge. The S glycoprotiens are neither identical nor unique in neither model structure nor the physicochemical profiles in different parts of the world. The Tunisian models are drastically biodiversity from the Chinese and Iranian models.